BACKGROUND: Patients with first-onset seizures commonly present to emergency centres (ECs). The differential diagnosis is broad, potentially life-threatening conditions need to be excluded, and these patients need to be correctly diagnosed and appropriately referred. There are currently no data on adults presenting with first-onset seizures to ECs in South Africa. OBJECTIVE: To review which investigations were performed on adults presenting with first-onset seizures to six ECs in the Western Cape Province. METHODS: A prospective, cross-sectional study was conducted from 1 July 2011 to 31 December 2011. All adults with first-onset seizures were included; children and trauma patients were excluded. Subgroup analyses were conducted regarding HIV status and inter-facility variation. RESULTS: A total of 309 patients were included. Computed tomography (CT) scans were planned in 218 (70.6%) patients, but only performed in 169; 96 (56.8%) showed abnormalities judged to be causative (infarction, intracerebral haemorrhage and atrophy being the most common). At least 80% of patients (n=247) received a full renal and electrolyte screen, blood glucose testing and a full haematological screen. Lumbar puncture (LP) was performed in 67 (21.7%) patients, with normal cerebrospinal fluid findings in 51 (76.1%). Only 27 (8%) patients had an electroencephalogram, of which 5 (18%) were abnormal. There was a statistically significant difference in the number of CT scans (p=0.002) and LPs (p<0.001) performed in the HIV-positive group (n=49). CONCLUSION: This study demonstrated inconsistency and wide local variance for all types of investigations done. It emphasises the need for a local guideline to direct doctors to appropriate investigations, ensuring better quality patient care and potential cost-saving.